Combined potentiometer and switching structure with improved radial contact pressure contact means

ABSTRACT

A combined potentiometer and switching structure including wiper contacts fixed to a shaft and having contacting engagement with an annular resistor and a pair of switching rings. The wiper contacts are located coincident, or in phase relation. The switching rings are each provided with an interrupted area, such areas are located in an arc complemental to the arc of the resistor and are circumferentially spaced apart a distance not greater than the length of the resistor contacting surface whereby, during rotation of the shafts, circuits connected to the switch rings are opened at different positions with respect to the resistor wiping contact. An annular supporting ring formed of electrical insulation material and provided with a central rib projecting from the inner surface thereof serves as a convenient mounting for the switch rings.

United States Patent Gerwitz [54] COMBINED POTENTIOMETER AND SWITCHING STRUCTURE WITH IMPROVED RADIAL CONTACT PRESSURE CONTACT MEANS [72] Inventor: Paul F. Gerwitz, West Covina, Calif.

[73] Assignee: Spectrol Electronics Corporation, City of Industry, Calif.

[22] Filed: June 1, 1970 [21] Appl. No.: 54,042

Related U.S. Application Data [62] Division of Ser. No. 828,618, May 28, 1969, Pat. No.

[52] U.S. Cl. ..200/8 A, 200/11 A [51] Int. Cl. ..I'I0lh 19/56, HOlh 21/56 [58] Field ofSearch ..200/11 D,8R,8A, 11A, 24,

200/25, 26, DIG. 7; 338/172 [5 6] References Cited UNITED STATES PATENTS 2,749,397 6/1956 Brown ..200/26 2,911,577 1l/l959 Pignone ..200/8R [151 3,679,848 1451 July 25, 1972 Primary Examiner-J. R. Scott Anorney-Harry G. Martin, Jr. and J. Raymond Curtin ABSTRACT A combined potentiometer and switching structure including wiper contacts fixed to a shaft and having contacting engagement with an annular resistor and a pair of switching rings. The wiper contacts are located coincident, or in phase relation. The switching rings are each provided with an interrupted area, such areas are located in an arc complemental to the arc of the resistor and are circumferentially spaced apart a distance not greater than the length of the resistor contacting surface whereby, during rotation of the shafts, circuits connected to the switch rings are opened at different positions with respect to the resistor wiping contact. An annular supporting ring formed of electrical insulation material and provided with a central rib projecting from the inner surface thereof serves as a convenient mounting for the switch rings.

2 Claims, 6 Drawing Figures PATENTEDJuws m2 3 SHEET 1 0F 3 FIG.|

PATENTEDJums I972 SHEET 3 OF 3 FIG. 4

FIG.6

COMBINED POTEN'I'IOMETER AND SWITCHING STRUCTURE WITH IMPROVED RADIAL CONTACT PRESSURE CONTACT MEANS This application is a divisional application of U.S. Pat. application Ser. No. 828,618 filed May 28, 1969, now U.S. Pat. No. 3,587,027.

BACKGROUND OF THE INVENTION It has been desirable in the past to connect switch actuators and potentiometer wiping contacts to a common shaft. When more than a single switch assembly is involved, the housing and casing structure become larger than desired. Accordingly, it is the chief object of this invention to provide a structure of the described which by virtue of special mounting means for certain of the parts permits one to obtain a small compact and efficient unit.

SUMMARY OF THE INVENTION This invention has to do with a combined potentiometer and circuit switching structure. The potentiometer is of the conventional annular type having a circular contacting surface engaged by a wiping contact fixed to a shaft. A second wiper contact is affixed to the shaft and is phased with the resistor wiper contact. This second contact engages a pair of conducting switch rings. A circuit is formed from the second wiper contact through each of the switch rings. The switch rings are formed with interrupted areas whereby, at difierent positions of the resistor wiper contact, the switching circuits are opened.

More particularly, the invention is directed to a structural arrangement which is economical to manufacture and convenient to assemble to produce a device having very small overall dimensions.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a structure embodying my invention;

FIG. 2 is an end elevation looking to the left, FIG. 1;

FIG. 3 is an enlarged sectional view taken on a line corresponding to line 3-3, FIG. 2;

FIG. 4 is a sectional view taken on line 44, FIG. 3;

FIG. 5 is an exploded view of the switch rings and resistor illustrating the orientation of such parts; and

FIG. 6 is a schematic diagram illustrating an arrangement of the resistor and switching rings.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus consists of a casing having sections 10, 11. The section 10 is formed with an end wall 12, having an inwardly extending cylindrical hub 13. The hub 13 is provided with a central aperture forming a bearing in which an enlarged portion 14 of an actuating shaft 15 is joumaled.

The casing section 11 is provided with a discoidal closure 16 which is formed with a central aperture arranged in axial alignment with the aperture in the flange l3 and forming a second bearing for the shaft 15. The end member 16 is attached to the section 11 by a clamp ring 17.

A resistor 18 of annular configuration is fixedly mounted in the section 11. The inner surface 20 of the resistor is a contact surface over which a wiper contact 21 is moved. The contact 21 is fixed on one end of an arcuate spring member 22, the opposite end of which is fixed to an arm 23 which, in turn, is fixedly secured to a sleeve 25 of insulating material fixedly secured to the shaft 15. A collector ring 27 is attached in conductive relation to the arm 23 and is connected to a terminal 28 by a brush 30.

The casing section 10 is formed at its inner end with a cylindrical flange 33 formed with an annular shoulder 34. The casing 11 is formed with a circular flange 35 snugly engaging the flange 33 and abutting against the shoulder 34. The sections are held together by a clamp ring 37.

A pair of switching rings 38, 40, are fixedly mounted in the flange 33 of the casing section 10. In the arrangement disclosed, the switching rings are mounted in an annular member 41, fixedly mounted in the flange 33 and having a flange 43 extending radially inwardly between the switch rings 38, 40. The inner contacting surfaces of the switch rings are engaged by a wiper contact 45 fixed on one end of an arcuate leaf spring member 46, the opposite end of which is fixed to an arm 47 which, in turn, is fixed to the sleeve 25. A collecting ring 50 is fixed in conducting relation to the arm 47, and is connected to a terminal 53 by a brush 54. The collector rings 27, 50, are separated by a ring of insulan'ng material 55.

The contacting surface 20 of the resistor 18 extends circumferentially less than 360 in the structure shown about 325. The switching rings 38, 40, are each formed with an interrupted area in their inner contacting surfaces. For economy in manufacture, these interrupted areas are preferably in the form of a notch 58 in ring 38, and a notch 60 in ring 40. The switch rings 38, 40 are fixed in the insulating member 41 with the notches 58, 60 spaced apart circumferentially a distance less than the circumferential extent of the effective contacting surface 20 of the resistor 18.

The switch ring 40 is connected to a terminal 70 by wire 71 conveniently extended through the apertures 63, 64 in the switching rings and member 41, see FIG. 3. The switching ring 38 is connected to a terminal 72 by wire 73. One end of the resistor 18 is connected to a terminal 75 by wire 76. Accordingly, a switching circuit is established from terminal 53 to terminal 70 through switching ring 40, and a second switching circuit is established through terminal 53 and terminal 72 through switch ring 38.

One convenient method of assemblying the switch rings with the interrupted areas in the desired phase relation involves forming the rings with through apertures 63. The member 41 is formed with a through aperture 64 in the flange 43. The apertures 63, 64 are aligned and a pin is extended through the apertures. The rings are pressed into the member 41, or otherwise secured therein, and the member 41 is pressed, or otherwise secured, in the section 10. The alignment pin is then removed and the wire 71 is run through the apertures and fixed to the ring 40. The sections l0, 11 are oriented and fixedly clamped together by the band 37. This method of assembly, together with the product provided with the openings necessary to accomplish the method, are the subject of a patent application Ser. No. 823,617, now US. Pat. No. 3,585,562 filed concurrently with this application and assigned to a common assignee. Another method of assembling the unit forming the subject of this invention would involve arranging the switch rings without apertures in proper position on the ring 41 with the aid of proper alignment indicia and securing same with adhesive material. An opening might then be formed in the base portion of the ring for a conductor. Such a procedure would not, of course, be as efficient as providing openings, in alignment, through the parts as described above.

In FIG. 6, the interrupted areas in the rings 38, 40 are indicated at 58, 60 and as being located coincident with the ends of the resistor 18. The wiper contacts 21, 45 are fixed in phase relation, see also FIG. 4. Accordingly, when the resistor wiper 21 is positioned at the right end of the resistor, the contact 45 is in register with the notch 58 in the switching ring 38. When the resistor wiper has been moved to the left end of the resistor, the contact 45 is in registration with the notch 60 in the switching ring 40. At intermediate positions of the wiper contacts, both switching circuits are energized.

It will be apparent the interrupted areas of the switching means may be phased to provide interruption of the switching circuits at various preselected positions of the resistor wiper contact 21.

While I have described a preferred embodiment of the invention, it will be understood the invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

I claim:

1. In combination with a casing including an end wall and a closure and a rotary shaft arranged within the casing, a switch module comprising a mounting ring formed of dielectric material assembled within the casing, said ring being provided with an annular rib projecting inwardly from the inner surface thereof, a first metallic ring disposed with the mounting ring on one side of the annular rib, a second metallic ring disposed within said mounting ring on the opposite side of the annular rib, and contact means mounted on said shaft for rotatable engagement with each of said metallic rings, at least one of said rings including a circumferential notch formed in the inner 

1. In combination with a casing including an end wall and a closure and a rotary shaft arranged within the casing, a switch module comprising a mounting ring formed of dielectric material assembled within the casing, said ring being provided with an annular rib projecting inwardly from the inner surface thereof, a first metallic ring disposed with the mounting ring on one side of the annular rib, a second metallic ring disposed within said mounting ring on the opposite side of the annular rib, and contact means mounted on said shaft for rotatable engagement with each of said metallic rings, at least one of said rings including a circumferential notch formed in the inner surface thereof over which the contact means moves in spaced relation to the ring so that a circuit through the contact and the ring is temporarily interrupted.
 2. The switch set forth in claim 1 wherein each ring is provided with notch formed in inner surface thereof and the rings are assembled within the mounting ring with the notches circumferentially spaced from one another to provide predetermined circuit interruption between each ring and the contact means. 